<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    body{
      margin: 0;
      padding: 0;
      background-image: url(../images/grid.png);
    }
    .box{
      width: 200px;
      height: 100px;
      background-color: skyblue;

      /* 形变 */
      /* transform: rotateZ(45deg); */

      /* 简写 */
      /* transform: rotate(45deg); */
      transform: rotate3d(0, 0, 1, 45deg);
    }
  </style>
</head>
<body>
  
  <div class="box">div</div>
</body>
</html>